1. Field of the Invention
The present invention relates to a photo film cartridge and a camera loaded therewith.
2. Background Arts
A well-known lens-fitted photo film unit is pre-loaded with a photo filmstrip at the time of manufacture. This lens-fitted photo film unit is widely used because of advantages that a user can take a photograph with easy operations just after purchase. The used lens-fitted photo film unit is collected by a maker, and disassembled into each functional unit or part. The functional unit or part is reused after inspections, or recycled as raw materials.
Various improvements have been made to the lens-fitted photo film units for the sake of increasing the reliability, so that some lens-fitted photo film units are reusable only by loading a new photo filmstrip therein. Thus, it is considered to turn the lens-fitted photo film unit into a simple camera, a photo film of which is easily changeable by a user. As for types of photo filmstrips employed in general cameras, 135-type and IX240-type have been widely used. Film processing systems in accordance with the photo filmstrips of ISO 135 or IX-240 format are installed in the great majority of photo labs, so it is possible to offer efficient printing service at a low cost.
The photo filmstrip of ISO 135 or IX-240 format is contained in a single-spool cassette. The cassette with the photo filmstrip is loaded into and taken out of the camera. Thus, in the general camera, the photo filmstrip has to be pulled out of the cassette frame-by-frame for photography, and then wound back to the cassette after making all exposures. Some cameras wind the photo filmstrip of all picture frames into a film roll chamber in advance of photography, and then take up the photo filmstrip frame-by-frame into the cassette every time a single exposure is made. For a lens-fitted photo film unit user, however, it is troublesome to wind all frames back after photography or to wind up all frames in advance.
Also a 110-type photo film cartridge is well known as a double-spool cartridge with a film roll chamber and a cassette chamber. Using the double-spool cartridge will make it easy to change a photo film because the wind back operation of all picture frames and wind up operation in advance are unnecessary. However, since the 110-type photo film cartridge has the film roll chamber and the cassette chamber, the cartridge itself is large in size, so that it is less convenient to carry anywhere. Also the 110-type photo film cartridge is not available to current film processing system suited for the 135-type and IX240-type photo filmstrips because of its specialty in shape, so that it will be difficult to carry out a film developing procedure efficiently.
An object of the present invention is to provide a photo film cartridge and a camera in which a loading and an ejection are easily carried out.
Another object of the present invention is to provide a photo film cartridge which is available to a current film development system to provide an efficient printing service at a low cost.
A further another object of the present invention is to provide a photo film cartridge which becomes small in size except when being loaded into a camera.
To achieve the above objects, in a photo film cartridge according to the present invention, a cartridge shell formed integrally out of plastic includes a cassette chamber for containing a cassette, a film roll chamber for containing a roll of photo filmstrip of ISO 135 or IX-240 format which is pulled out of the cassette, and abridge provided between the cassette chamber and the film roll chamber for guiding the photo filmstrip. In the bridge, there is formed an exposure frame for exposing a single picture frame of the photo filmstrip.
The photo film cartridge has a light shielding portion for preventing the unexposed photo filmstrip from being exposed. As the light shielding portion, for example, there is a pair pieces of plates with plush fixed between the film roll chamber and the exposure frame or a removable light shielding plate covering the front of the exposure frame.
In another embodiment a cartridge shell comprises two units, namely, a film take-up unit having a cassette chamber and a bridge, and a film supply unit having a film roll chamber and another bridge. In this case, one of the bridges is provided with a projection, and the other bridge is provided with a slot for engaging with the projection. Furthermore, the both bridges are movably fitted into each other within the confines of a length of the slot. Accordingly, except when the photo film cartridge is loaded into a camera, the cartridge shell becomes small in size for the sake of portability since the projection is positioned at one end of the slot. On the other hand, when loading the photo film cartridge into the camera, the cartridge shell becomes in a necessary size since the projection is positioned at the other end of the slot.
In each bridge a cutout is formed. When the bridges are fitted into each other, the cutouts of the both units form an exposure frame. When loading the photo film cartridge into the camera, the exposure frame is in a size of a single picture frame.
In addition to that, a click mechanism may be provided in both ends of the slot in order to secure the projection at either end of the slot. In this case, it is possible to handle the photo film cartridge with stability.